Microbially derived surfactants, so-called biosurfactants, have attracted significant attention as an environmentally friendly alternative to their chemically synthesized counterparts. Particularly, rhamnolipids offer a large potential with their outstanding surfactant properties such as complete biodegradability, low toxicity, and stability. https://www.selleckchem.com/products/cc-92480.html Rhamnolipids are naturally synthesized by the opportunistic human pathogen Pseudomonas aeruginosa under the tight regulation of a highly complex quorum-sensing system. The heterologous production of mono-rhamnolipids by a newly isolated nonpathogenic strain of the genus Pantoea was investigated. Analysis of the genome obtained by a chimeric assembly of Nanopore long reads and high-quality Illumina reads suggested that the strain has evolved to an epiphytic rather than a pathogenic lifestyle. Functional heterologous expression of the mono-rhamnolipid operon rhlAB derived from a P.&nbsp;aeruginosa strain was established and confirmed by HPLC analysis. Transcriptome analysis indicated destabilizing effects of the produced rhamnolipids on the cell envelope of the host resulting in the induction of molecular stress responses. After integration of the rmlBCDA operon, extracellular rhamnolipids in amounts up to 0.4&nbsp;g/L could be detected and were identified as a mono-rhamnolipid Rha-C10 -C10 by MALDI-TOF mass spectrometry. © 2020 The Authors. MicrobiologyOpen published by John Wiley &amp; Sons Ltd.Per- and poly-fluoroalkyl substances (PFAS) are a broad class of environmentally persistent chemicals that include thousands of potentially toxic synthetic organic molecules. Some PFAS have been shown to cause adverse health effects including decreased total cholesterol, birth weight, and reproductive success in laboratory animals; however, a lack of chronic toxicity data exists for PFAS in avian ecological receptors. The present study reports the chronic toxicity of perfluorooctane sulfonic acid (PFOS) and a mixture of PFOS and perfluorohexane sulfonic acid (PFHxS) to Northern Bobwhite quail (Colinus virginianus) via oral exposure from drinking water. Female weight gain was significantly adversely affected at an average daily intake (ADI) of 3.10x10-3 ± 0.15x10-3 mg PFOSPFHxS (1.21) mixture x kg-1 body weight x day-1 . Successful liberation from shell once pipped was significantly adversely affected at an ADI of 2.45x10-3 ± 0.01x10-3 mg PFOS x kg-1 body weight x day-1 . These values are comparatively much lower than the current dietary avian toxicity reference value (TRV) where birds were exposed via the feed suggesting the need for updated avian TRVs. Relationships between test chemical (PFOS) and test substance (PFOSPFHxS) showed that PFOS and PFHxS have possible interacting effects in avian receptors and likely differing mechanisms of toxicity depending on chemical co-occurrence and dose. Both the single chemical and mixture exposures produced similar and possibly additive toxicity values. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.OBJECTIVES The bubble-positive expiratory pressure (PEP) device may be used for sputum clearance in people with daily sputum production. However, this device has never been studied in people with bronchiectasis. Hence, the objective of this study was to compare the effect of bubble-PEP device, the active cycle of breathing technique (ACBT) and no intervention (control) on sputum clearance in people with bronchiectasis. METHODS This was a prospective, randomised cross-over trial with concealed allocation, assessor blinding and intention-to-treat analysis. Adult participants with stable bronchiectasis and productive of sputum daily were recruited. Participants performed 30-min of bubble-PEP, ACBT or control in random order whilst sitting, followed by 60-min of quiet sitting, on three separate days at the same time within a 10-day period. Primary outcome measure was wet weight of expectorated sputum during 30-min intervention, 60-min post intervention and total wet weight (30 min plus 60 min). RESULTS Thirty-five-participants (11 males, mean [standard deviation] age 75 [8] years, forced expiratory volume in 1 s 72 [20] % predicted) were recruited and 34 completed the study. There was no significant difference in sputum wet weight between bubble-PEP and ACBT during 30-min intervention (mean difference [95% confidence interval]) -0.59?g [-1.37, 0.19] and total wet weight (0.74?g [-0.54, 2.02]). Sputum wet weight was significantly greater in bubble-PEP than ACBT at 60-min post intervention (1.33?g [0.19, 2.47]). CONCLUSION Sputum wet weight was significantly greater with bubble-PEP than control at all time periods, and greater than ACBT at 60-min-post. Bubble-PEP could be considered an alternative sputum clearance technique to ACBT. © 2020 John Wiley &amp; Sons, Ltd.The marine sulfur cycle is substantially fueled by the phytoplankton osmolyte dimethylsulfoniopropionate (DMSP). This metabolite can be metabolized by bacteria, which results in the emission of the volatile sulfur species methanethiol (MeSH) and the climate-cooling dimethylsulfide (DMS). It is generally accepted that bacteria contribute significantly to DMSP turnover. We show that the other low molecular weight zwitterionic dimethylsulfonio compounds dimethylsulfonioacetate (DMSA) and gonyol are also widely distributed in phytoplankton and can serve as alternative substrates for volatile production. DMSA was found in 11 of the 16 surveyed phytoplankton species, and gonyol was detected in all haptophytes and dinoflagellates. These prevalent zwitterions are also metabolized by marine bacteria. The patterns of bacterial MeSH and DMS release were dependent on the zwitterions present. Certain bacteria metabolize DMSA and gonyol and release MeSH, in others gonyol inhibited DMS-producing enzymes. If added in addition to DMSP, gonyol entirely inhibited the formation of volatiles in Ruegeria pomeroyi. In contrast, no substantial effect of this compound was observed in the DMSP metabolism of Halomonas sp. We argue that the production of DMSA and gonyol and their inhibitory properties on the release of volatiles from DMSP has the potential to modulate planktonic sulfur cycling between species. © 2020 The Authors. MicrobiologyOpen published by John Wiley &amp; Sons Ltd.